Retirement Benefits (Schedule of Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
US [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 10.6	$ 10.7
Interest cost	31.2	32.7
Expected return on plan assets	(50.5)	(47.0)
Actuarial loss amortization	19.8	19.6
Prior service cost amortization	0.7	0.7
Settlement and curtailment charges	(0.1)	0
Special termination benefits	2.7	0.2
Other	1.1	0
Net periodic benefit cost	15.5	16.9
International [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	8.2	8.8
Interest cost	15.0	16.6
Expected return on plan assets	(21.1)	(19.2)
Actuarial loss amortization	10.5	8.8
Prior service cost amortization	0	0.1
Settlement and curtailment charges	(0.1)	0
Special termination benefits	0	0
Other	0.5	0.5
Net periodic benefit cost	13.0	15.6
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.7	0.8
Interest cost	0.6	0.6
Expected return on plan assets	0	0
Actuarial loss amortization	0.2	0.4
Prior service cost amortization	0	0
Settlement and curtailment charges	0	0
Special termination benefits	0	0
Other	0	0
Net periodic benefit cost	$ 1.5	$ 1.8